<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Document</title>
  <style>
    div {
      width: 100px;
      height: 100px;
      margin: 100px auto;
      background-image: repeating-radial-gradient(circle at left bottom, 
      #ccc 0, #ccc 10%, #fff 10%, #fff 20%);
      transform: rotate(-45deg);
      border-radius: 0 100px 0 0;
    }
  </style>
</head>
<body>
  <div></div>
</body>
</html>